1#include <string.h>
 2#include <stdint.h>
 3#include <limits.h>
 4
 5#define ALIGN (sizeof(size_t))
 6#define ONES ((size_t)-1/UCHAR_MAX)
 7#define HIGHS (ONES * (UCHAR_MAX/2+1))
 8#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
 9
10char *__strchrnul(const char *s, int c)
11{
12	c = (unsigned char)c;
13	if (!c) return (char *)s + strlen(s);
14
15#ifdef __GNUC__
16	typedef size_t __attribute__((__may_alias__)) word;
17	const word *w;
18	for (; (uintptr_t)s % ALIGN; s++)
19		if (!*s || *(unsigned char *)s == c) return (char *)s;
20	size_t k = ONES * c;
21	for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w^k); w++);
22	s = (void *)w;
23#endif
24	for (; *s && *(unsigned char *)s != c; s++);
25	return (char *)s;
26}
27
28weak_alias(__strchrnul, strchrnul);